1. Field of the Invention
The present invention relates, in general, to a knee bolster for vehicles and, more particularly, to a knee bolster for vehicles, which achieves compliance with the pedestrian protection regulations of the reinforced North American NCAP (New Car Assessment Program) in crash tests and can minimize the production cost, and can simplify the production process.
2. Description of Related Art
Generally, in car accidents, passengers including the driver sitting in the front seat of a vehicle move forwards and come into contact with the lower instrument panel placed in front of the front seats. In the above state, when the lower instrument panel is easily deformed, the knees of the front passengers may exceedingly move forwards so that the heads and chests of the passengers may lean backwards too much and airbags may fail to successfully protect the passengers from the crash energy. In an effort to solve such a problem, a knee bolster is installed inside the lower instrument panel placed in front of the front seats such that the knee bolster can prevent the knees of the front passengers from moving deeply in towards the lower instrument panel and can absorb the crash energy in case of an accident.
Therefore, the knee bolster is designated as a restraining device which can control the posture of a front passenger in an accident such that the knee movement of the front seat passenger can be limited and the crash energy can be evenly distributed to the upper and lower parts of the passenger's body. The knee bolster can keep the damage done to the knees of a front passenger within a predetermined level and can prevent the knees of the front passenger from moving too deeply into the lower instrument panel in case of an accident, thus allowing the passenger to be successfully protected by an airbag. The limits of knee load, chest load and chest displacement in accidents are set out by regulations. Thus, when producing vehicles, it is important to achieve compliance with the regulations of respective localities. Further, improving the performance of vehicles to maximize the commercial value of the vehicles is recognized as an important task for respective local commercial value tests.
FIG. 1 is a perspective view illustrating the construction of a conventional knee bolster for vehicles. As shown in FIG. 1, the conventional knee bolster includes an L-shaped knee bolster bracket 2 mounted to a cowl cross bar 1, a reinforcing bracket 3 held in back of the knee bolster bracket 2, and a knee bolster plate (not shown) installed in front of the knee bolster bracket 2.
When the knee load of a front passenger is applied to the conventional knee bolster in an accident, the knee bolster bracket 2 receives most of the knee load and the reinforcing bracket 3 controls the strain and the penetration rate.
However, the conventional knee bolster is designed such that absorption of the knee load in an accident can be realized by the knee bolster bracket 2 deforming, so that the conventional knee bolster cannot efficiently absorb the load applied to the knees of the passenger and does not achieve compliance with the pedestrian protection regulations of the reinforced North American NCAP. Described in detail, although the pedestrian protection regulations of the former North American NCAP required a knee load not exceeding 10 kN as being an allowable reference load, the pedestrian protection regulations of the reinforced North American NCAP require the knee load to not exceed 2.8 kN. However, the conventional knee bolster technique cannot achieve compliance with the pedestrian protection regulations of the reinforced North American NCAP.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.